As a review . . . to create the initial barrels the blanks are:
1) Drilled to the proper diameter, depending on caliber.
2) Honed to a high polish smoothness along the entire length.
3) Given rifling using the hammer forging process which uses a mandrel and huge pressures generated by “hammers” in the machine.
These blanks look beautiful at this point but this is just the beginning. They are taken to a station consisting of three CNC (Computer Numerical Control) machines overseen by one expert operator. At the first station the barrel blank is turned to the correct profile (taper). This creates a surface finish so smooth that no further polishing would be necessary if these were made for lesser brands.
A tour of outdoor writers gather around the machine that cuts the barrel profile. The finished barrel mirror smooth at this point.
The turned barrel is moved to the next machine which precisely cuts the target crown into the muzzle. This type of recessed crown is proven the best at protecting the fine edge of the muzzle from damage.
The third station carefully rough cuts the chamber in a multi-stage operation. The chamber end of the barrel is then threaded, and this same machine cuts the excess piece of barrel still attached just after the threads. This extra material was used for gripping in the machines.
In a hands-on procedure, the operator completes the process by hand polishing/honing the interior of the chamber to a smooth surface. This assures that feeding and extraction will be smooth and flawless. The Model 70s well-known “cone” is also cut into the breach at this time.
Honing the chamber.
This image shows the process from right to left starting with the blank and ending with the finished barrel.
From here the barrels are mated with receivers and are screwed on and properly torqued. These receivers have been prepared earlier and are fully polished, ready to go. Like the original Pre-’64 rifles, the receivers are forged from a solid piece of steel then CNC cut to correct dimensions for internal fits of the chamber, bolt, safety components, etc.
The barrel and receivers are indexed with a mark and then taken apart again. From this time on the same barrel and receiver stay associated with each other. After being taking apart, the barrels go to a special barrel polishing machine that is unique in the business.